An event generated by touching a touchscreen of a terminal by a user is referred to as a touch event, and is also referred to as a touch control event. Generally, an event processor in an Android system directly sends a received touch event to a current interface, that is, a user interface of an application program running in a foreground. The application program processes the touch event by using a corresponding processing method. The application program running in the foreground refers to an application program whose display interface is visible on a screen and that can be used for direct interaction with a user.
The display interface of the application program in the Android system includes an underlying page and a control response area arranged on the underlying page, where a control may be a button or a text area. If a position in which a touch event is performed is in a control response area, an event processor reports the touch event to an application program corresponding to the control response area; or if a position in which a touch event is performed is not in the control response area, the touch event is sent to the underlying page. Generally, the underlying page does not respond to the touch event. Because the underlying page is the last stage for event processing, the touch event to which the underlying page does not respond disappears. If some touch points of a multi-point touch event are not in the control response area of the application program, it is determined that the multi-point touch event is initiated to the underlying page, and the multi-point touch event is reported to the underlying page. For example, if there is a water droplet on a touchscreen, a tap performed by a user on a phone button to answer an incoming call may not be responded to. In the Android system, the water droplet and the taps performed by the user are regarded as a multi-point touch event, and therefore the multi-point touch event is reported to the underlying page. However, the underlying page does not respond to the touch event; consequently, the touch event disappears, that is, the touch operation performed by the user is not responded to.
In some scenarios, when a touchscreen is in an enabled state, even if the touchscreen is not touched by a user, the touchscreen is touched automatically and arbitrarily. It seems that an invisible hand is touching the touchscreen, and this is commonly known as a ghost hand. It can be learned from the foregoing touch event process flow that, when a ghost hand appears on a screen, or a touch event is incorrectly reported because of a factor such as a hand-grip gesture of a user or an external situation (for example, there is a water droplet on the screen), the touch performed by the user on a specified position is not responded to.